We propose the creation of a Midwest AIDS Biobehavioral Research Center (MABRC) which focuses on decision-making processed determining behavioral co-factors of HIV infection and clinical outcomes. The primary role of the Center will be to support and perform biobehavioral research which is directly relevant to AIDS and the control of HIV infection. To accomplish this, the Center will initially consist of a set of closely interrelated core research projects, core research, administrative and information dissemination support facilities, and a number of Center satellite facilities and projects in Detroit and Chicago. We expect the over the course of the Center's initial five years, both the number of associated biobehavioral research projects and their diversity will increase significantly. The Center draws on the extensive experience on its key faculty in the field of biobehavioral research related to AIDS and close ties to the public health sector and community service organizations where the results of the Center's research activities will be applied. Each initial core research project of the Center looks at the process of decision making from a different but interrelated perspective. The Behavioral Medicine project will examine the mechanisms underlying the effects of arousal and drugs of abuse on sexual behavior decision making. In parallel the Psychiommunology project will examine the mechanisms by which arousal and drugs, of abuse such as are significant psychosocial co-factors determining the immunological and clinical outcomes of HIV infection. The multi-centered cohort will be created as part of the INAPEN project will provide the first opportunity to examine prospectively such factors as drug use, of transmission, social support networks, levels of stress, etc., bases in support of its own research projects which will be made available through national computer networks to all AIDS researchers throughout the United States. The initial Center Satellites have been chosen to provide collaborative links between Core Center researchers and AIDS biobehavioral researchers in other Midwestern cities. Both the Satellites and the Center will seek to increase the involvement of minority researchers and community-based organizations in AIDS biobehavioral research and related training opportunities.